BOSTON – A survivor of the Boston Marathon attacks has written an indignant open letter to the admitted bomber.

Rebekah Gregory lost a leg in the 2013 bombings and wrote the letter to Dzhokhar Tsarnaev (joh-HAHR' tsahr-NEYE'-ehv) on her Facebook page after she testified in his federal death penalty trial earlier this week.

In the letter, Gregory says sitting near Tsarnaev in court brought her a surprising sense of peace and closure. She writes, "Today I looked at you right in the face ... and realized I wasn't afraid anymore."

She says she considers Tsarnaev "a nobody" and signs her letter: "Someone you shouldn't have messed with."

As of Friday morning, Gregory's letter had more than 33,000 likes and more than 9,500 shares on Facebook.